I've noticed that transmuters usually have both sides of the coin in their spells. You gots your disrupt bone, but you also have your repair bone. You have your gill growth, but you also have your gill removal. In the spirit of this I propose a new spell to opposite Occular Enhancement.
I was thinking along the lines of "Occular Deterioration." If they can enhance it, why can't they screw it up?

This spell, as the name implies, would deteriorate the targets vision rendering them unable to utilize some of the finer points of being able to see clearly.
This of course wouldn't be straight blind - that would be boring.
What I propose it should do is:

1) They are able to see people in the room, but are unable to see hidden/invisible/camo.

2)They would be able to see what room they're in, but not its description. (Like a forced brief mode)

3)They would be able to look at people, but not see what those people are wearing. (It would all be "Something")

4) They would still be able to initiate attacks, but unable to use disarm. (beause they cannot see the weapon well enough)

5)They would be rendered unable to do the following: Scan, see hidden/invis/camo, (as aforementioned) and see in the dark.

6)They would have a chance to manipulate the wrong item in their inventory (I.e, trying to wield a steak instead of a sword) and are unable to manipulate potions at all.

I kinda thought this should stop the target from using "where" as well, but thats probably a bit too nasty.

I - having played a few muters - think this would be a welcome addition to their repertoire, and add a few more options for lower level combat.
Thanks for your time ;)
-Drekten.